Metadata

Coordinates

This station was deployed in the same field as Station D13 (Roberts Island Alfalfa) aproximately 50 m north of Station D13.

Elevation

Deployment Dates

Deployed: 2016-09-08
Removed: N/A

Sensors Deployed

  • 1 CNR4 (Kipp & Zonen) four-stream net radiometer mounted at 1.3 m above ground level
  • 2 FW3 (Campbell Scientific) fine-wire thermocouples mounted at 1.5 m above ground level
  • 1 IRGASON (Campbell Scientific) ultrasonic anemometer combined with an infrared gas analyzer mounted at 1.5 m above ground level
  • 1 HC2S3 (Rotronic) Temperature/Relative Humidity Probe mounted at 1.62 m above ground level
  • 3 REBS ground heat flux plates inserted at 0.05 m below the soil surface
  • 3 TCAV (Campbell Scientific) averaging soil thermocouples inserted between 0.04 and 0.01 m below the soil surface
  • 3 EC5 (Decagon) volumetric water content sensors inserted at 0.05 m below the soil surface

Notes

  • Much of the winter data, especially IRGASON LE may be unreliable due to precipitation and/or condensation on the sensor window. This data should be interpreted with caution.

  • The IRGASON was oriented North. Sonic anemometer variables were set to NA in the quality control processing step when the wind direction was within 45 degrees of South (coming from South of the IRGASON) to avoid periods when the IRGASON itself would upwind of the sampling volume.

  • Surface renewal sensible heat flux measurements were corrected with calibration coefficients developed between surface renewal and eddy covariance measurements.

  • Sensible and latent heat fluxes measured by the IRGASON were multiplied by 1.08 to account for the effect of wakes formed by the transducers of the instrument and to adjust for typical spectral loss (Horst et al. 2016, Kochendorfer and Paw U, 2011).

  • There was a wiring problem with the CNR4 radiometer until it was fixed on 10/26. No measurements from the CNR4 are available before that.

  • High frequency wind and temperature data used for eddy covariance and surface renewal were collected at 10Hz on CF cards (rather than processed on the datalogger itself like the other stations). Given capacity of these cards and timing of our field vists, some data was overwritten and lost. There are three such gaps encompassing most of November, and much of January and March.

  • There is an unknown problem with all of the ground heat flux plates and EC5 soil moisture sensors - none of the data are reasonable. We are continuing to try to diagnose the issue. Therefore the residual ET estimates presented in this data use the G measurements from the main D13 station (in the same field).

  • On March 2nd we found the rain gauge clogged with debris. We unclogged it and let the standing water proceed to be measured. The spike on that day represents precipitation accumulated since early January (when there was significant rainfall) minus any evaporation while the water was standing exposed in the clogged gauge.

Daily Evapotranspiration and Energy Balance Components

Summed daily net radiation (Rn), ground heat flux (G), surface renewal derived sensible heat flux (H SR), eddy covariance derived sensible heat flux (H EC), and the resulting actual evapotranspiration derived from the energy balance residuals (ETa SR and ETa EC).Also plotted is daily reference evapotranspiration provided by Spatial CIMIS (ETo).

Columns plotted: Rn_Avg_gf_mm_Dqc, SR_aH_gf_mm_Dqc, H_ECrot_gf_mm_Dqc, G_gf_mm_Dgf, ET_SR_aH_qc_Dgf, ET_EC_qc_Dgf, IRGASON_ET_WPL_gf_Dqc, ETo_mm


Daily ETa / ETo

Daily calculated ETa divided by daily ETo obtained from Spatial CIMIS.

Columns plotted: Ka_SR, Ka_EC, Ka_IRGASON


Half-hourly Energy Balance Components

Average net radiation (Rn),calibrated surface renewal derived sensible heat flux from each thermocouple (H Tc and H Tn), average of the sensible heat fluxes measured by each thermocouple (H SR), ground heat flux (G), and sensible heat flux derived from eddy covariance (H EC). Also included are the latent energy fluxes calculated by residual for the surface renewal (LE SR) and eddy covariance (LE EC) sensible heat fluxes.

Columns plotted: Rn_Avg_qc, SR_aH_qc, Tc_aH_qc, Tn_aH_qc, G_qc, H_ECrot_qc, LE_SR_aH_qc, LE_EC_qc, IRGASON_LE_WPL_qc


Calibration of Surface Renewal Sensible Heat Fluxes against Eddy covariance

Average half-hourly sensible heat flux from surface renewal estimates (average of the individual thermocouples) plotted against the half-hourly average H from eddy covariance. The intercept of the the regression line is forced to zero and the slope is the coefficient used to calibrate the surface renewal flux. Half-hours with positive and negative heat fluxes are plotted and calibrated seperately

Columns plotted: H_ECrot_qc, SR_H_qc


Daily Total Precipitation

On March 2nd we found the rain gauge clogged with debris. We unclogged it and let the standing water proceed to be measured. The spike on that day represents precipitation accumulated since early January (when there was significant rainfall) minus any evaporation while the water was standing exposed in the clogged gauge.

Columns plotted: Pcp_Tot


Half-hourly Average Wind Speed

Half-hourly averaged wind speed measured by the ultrasonic anemometer.


Half-hourly Wind Direction

Half-hourly wind direction calculated from half-hourly averaged wind components.


Wind Rose Diagrams

Wind rose diagrams showing the distribution of wind direction and speed during daytime and nighttime periods.


Half-hourly Average Temperature

Half-hourly Average temperature measured by each thermocouple (Tc and Tn), the HC2S3 air temperature probe (Ta), and by the internal datalogger reference (Tpanel). The dewpoint temperature (Td) is calculated from the air temperature and relative humidity measured by the HC2S3.

Columns plotted: Tpanel_qc, Tc0_Avg_qc, Tn0_Avg_qc, Ta_Avg_qc, Td_Avg_qc


Half-hourly Relative Humidity

Half-hourly relative humidity measured by the HC2S3 probe.

Columuns plotted: RH_qc


Half-hourly Average Soil Temperature

Half-hourly Average Soil Temperature


Half-hourly Average Battery Voltage

Half-hourly datalogger battery voltage.